Power-pneumatic for player-pianos.



J. LBISGH.

POWER PNEUMATIC FOR PLAYER PIANOS.

APPLICATION FILED OUT. 23. 1911.

Patented July'8, 1913.

4 I i l I mer up to the strin UNITED STATES PATENT OFFICE.

JOSEPH LEISCH, or 'rRYoN, NORTH CAROLINA, ASSIGNOR TO THE- JOHN CHURCH COMPANY, or CINCINNATI, OHIO, A CORPORATION or OHIO.

P@\VER-PNEUMATIC FOR PLAYER-PIANOS.

Specification of Letters Patent.

Application filed October 23, 1911. Serial No.'65c,249.

T 0 all whom it may concern:

lie it known that I, JOSEPH LEISOH, a citizen of the United States, and a resident of Tryon, in the county of Polk and State of North Carolina, have invented certain new and useful Improvements in Power- Pneumatics for Player-Pianos, of which the following is a full, clear, and exact description, reference being bad to the accompanying (lrmving, forming part. of this specification.

The object of.my invention is to provide a construction for regulating-the action ot" the pneumatic whereby the mechanical movement of the pneumatic may be made to simulate the human touch of the musician in playing the keys of a piano in the ordinary way.

In ordinary piano action constructions, when the sticker. of the piano action has been raised high enough to bring the hama release takes place, which is governed, y a regulating screw on the jack. When this happens, the ham mer bounds back and is checked until the jack can fly back underneath the hammer-. butt, preparatory for another stroke of the key. During this action, the key has reached the bottom of its'stroke, but. there is usuallya slight space between the point where the key is released and the cushion underneath the key. Many'musicians have different ideas as tohow much of a space this should be, and the vivacity of touch is determined by this space. The musician in playing unconsciously tends to release the key before it reaches the bot-tom of its stroke, and thus the .pressureon the key is subject to a check not entirely mechanical and the actuation of the piano keysis different from a-imere mechanical stroke.

My invention consists-in providing, in-

. steadof a fixed stop, an ad) ustable resilient stop for thepneumaticwhich can be. regulated to suit the desires and -re'quirenients of the individual operator as hereinafter particularly pointed out and claimed,where by an elfect may be 'roduced, that. shall simulate more nearly t e human touch. A

In the drawing, Figure l is a side eleva' 7 tion of my improved construction. Fig. 2. is a central ongitudinal section/ofthe same. Fig. 3 is a top plan view. 4 is an in-' side perspective view of the pneumatic.

The pneumatic" of the usual hellows' type ,is made of ainovable member-.18 with an:

' Patented July 8 1 913. 1

extension 14:, to contact with and actuate pouch and valve for actuating the pneumatic.

12 is the valve chamber, with valve seat plates 6 and 7, and in which is mounted the double valve comprising the valve disks 8 and 18, with the stem 19 carrying the button head 20 projecting downwardly into the vacuum chamber 10 and resting onthe pouch 9, covering the passageway 11, which extends to the primary valve or tracker board. The valve chamber 12 is connected by the passageway 5 with the interior of the pneumatic.

WVhen the air is released, through passage 11, through the tracker-1 boardin the usual way, the pouch 9 is V flated, which raises the valve, closingdiskf- 'Sagainst the seat plate 7 and thus cutting off the outer air and raising thev valve disk.

18 to open the vacuum chamber to the pas- Saga 5 into the pneumatic, and actuates the pneumatic in the usual way to-cause the extension. 14 to raise the sticker of the piano 1 action.

Mounted inside-the bellows pneumatic 1s a strip of spring metal 1, which is securedby screws or otherwise near. the inner end of the fixed member of the pneumatic and the free end of which bears upon the 'innerend of a screw capstan 4. The spring is adjusted toward and. away from the movable member 13 by thecaypstan 4, mounted in and ex tending through the fixed. member of the pneumatic,'while underneath this spring plate on the movable member is located the cushion 3, so that instead of the" cushion coming in contact with a fixed abutment, it

comes in contact with the spring. A cash-- ion or strip of felt 21 is also provided to prevent any metallic contact with the end of the regulating capstan, and thjespring 1 is likewise provided with a felt washer for the same purpose. the spring is regulated for distance .of stroke, resiliency of touch and to absorb any shock in the mechanical movement. In adjusting the stroke by the capstan 1, the lift of the extension 14 should be just sufiicient to lift the hammer of the piano act-ion and operate the release. In making'this adjustment, it might sometimes happen that'the maximum benefit of the spring 1 couldnot- By adjusting the capstan,.

posit-ions of adjustment. In this way, the

be obtained with the cushion 3 in fixed position. The cushion 3 is therefore preferably mounted on a screw 24 which projects through a slot'22 in the member 13 or the pneumatic while a plate 23 isa-ttaehed to the screw either inside or outside the pneumatic, to cover'the slotted opening for all cushion can also be adjusted for its contact with the spring. hen very slight resilient effect is desired, the capstan will be with- -drawn so as'to provide for a full stroke of as the unconscious check given by the human finger 1n striking-the keys Hi the ordinary playing of the instrument, and this checking of the stroke of the pneumatic may be regu lated with great delicacy, thus tending to simulate the human touch. More than this,

"cushion'on said movable member for the and of special importance is the effect of the spring in returning the movablenmmber of the pneumatic to its normal the resilient impulse.

It is evident in playing the keysof a piano, that rapidity of stroke depends for one thing on the rapidity of withdrawal of the finger afterthe'key has been struck. It is also evident. that rapidaction of the pneumatic is dependent .on the quick return of the movable member. ,Withiny construction, the resiliency of the spring instantly positician under returns the movable member so thatextreme rapidity of stroke is attainable.-

Having thus described my invention, what I claim as new and desire to secure by Let- .ters Patent, is

I 1. In a player piano,- a power pneumatic having a movable member, a yielding spring to form a check stop and return for the movable member, and an adjustable unyielding stop for said member, a. contact fixed stop, and an adjustably mounted cush ion on said member for the spring stop.

2. In a player piano, a power pneumatic having a movablemember and a fixed memher, a yielding spring mounted inside of the pneumatic to form a check stop and return for the movable member, and an adjustable unyielding stop for said member, acontact :cushionon said movable member for the fixed stop-and an 'adjustably mou'nted'cusln ion on said member for the spring stop.

3. In a player piano, a powerpne'umatic having a movable member, a yielding spring with means for ad usting the position of the return for the movable member, said adjusting means also adapted to form a fixed stop for said member, and separate contact cushions on said member for each stop.

a. In a player piano, a power pneumatic having a movable member, a stop for the movable member normally out of contact therewith comprising a strip of resilient metal, with an adjusting screw to regulate tion of the stop, said screw arranged so as to form a fixed stop for said member and separate contact cushions on said member for each stop.

5. In a player piano, a power pneumatic having a movable memberand a fixed'member, a stop for the movable member thereof comprising a strip of resilient metal, secured at one endto the fixed member and normally out of contact with the movable member, with a capstan adjustable from outside the pneumatic against which the free end of the spring abuts to adjust the position of the free end of the strip, and separate con- 6. Ina player piano, a power pneumatic having a movable member, a fixed stop for the movable member, a stop for the movable member comprising a strip of resilient metal abutting against tire fixed stop and nornally out of contact with the movable member, mounted within the pneumatic to serve as an adjustable 'stop therefor, with .an adjustable cushion on the. movable member to vary the point of contact therewith, meaiis for adjusting the fixed stop for said member.

7. In a player piano, a power pneumatic having a movable member and a fixed member, a stop for the movable member thereof, comprising a strip of resilient metal, secured at one end to the fixed member and normally out of contact with the movable member, with an adjusting screw to regulate the position of the free end. to vary the-position of the stop and the amount of. movement of the movable member of the pneumatic, with an adjustable cushion to conform to the adj ustment'of the spring, and an additional cushion on the movable member shorter in height than the said adjustable cushion for contact with the; ad usting screw. Y ,1 V JOSEPH LEISCH.

Attest: R. I. HARGITT,

EARL W. GRIFFIN.

spring to form an adjustable check, stop and said movable member and a contact cushion. therefor on on the movable me nher to vary the point of contact'therewith the position of the free end to vary'the positact cushions on said member for each stop. 

